Roller



Jan. 20, 1942.

J. N. SUMMERS ROLLER Filed April 29, 1959 2 She'ts-Sheet 1 Patented Jan. 20, 1942 UNITED STATES PATENT OFFICE ROLLER Joe N. Summers, Mission, Tex. Application April 29, 1939, Serial No. 270,939

' Claims.

The invention relates to rollers and has as an object the provision of means to cause a plurality of rolling elements to act on uneven ground with substantially equal pressure across the width of the device. v

A further object of the invention is to provide a roller comprising a plurality of individual roller elements in the form of wheels, each element relatively movable in a vertical direction relative to the other elements and to the frame to whichall are connected; to provide means for preserving an approximately even pressure at all times on each of a plurality of roller elements; to provide for such uniform pressure by hydraulic means; to provide a plurality of hydraulic cylinders in communication with a common reservoir, for maintaining such uniform pressure and with convenient means to replace any loss of fluid as by leakage; to provide pressure equalizing means for the respective roller elements with means to produce an adjustable modification of the equalizing action.

Further objects of the invention will appear from the following description when read in connection with the accompanying drawings showing illustrative embodiments of the invention, and wherein: I Figure 1 is a side elevation;

Fig. 2 is a plan view;

Fig. 3 is an end levation seen from the left of Figure 1;

Fig. 4 is a detail vertical sectionon line 4-4 of Figure 2; and

Fig. 5 is a detail vertical section of a different form of the device.

As shown the device comprises a chassis frame It having a fifth wheel ll whereby the forward set of rollers l2 may be steered as drawn by a tongue member l3.

The rollers are shown as provided in two sets of elements, front and rear, wherein the rollers ll of the front set are in staggered relation with the rollers ii of the rear set. Each individual roller of each set is individually mounted on its own axle as at It, each axle shown as drawn by a pair of links ",th rear set pivoted upon a common shaft I 8, and the front set upon a common shaft l9. Accordingly the rollers are individually free to yield upwardly or to drop downwardly in response to face under treatment.

To cause uniform pressure upon all of the elements of each set, there is shown a piston rod pivoted to the links I I of the individual elements upon unevenness of the sura shaft 2|, the piston rod connected with a piston 22 reciprocable in a cylinder 23 opening into a manifold cylinder 24 in communication with all or a plurality of the cylinders of the set of which the rolling element is a member.

To keep a supply of liquid, as oil, in the cylinder 24 full to the capacity of the cylinder, there is shown supply drums 25, 26 for the front and rear sets of rollers respectively. As shown the rear set is provided with two of the cylinders 24', it being understood that one cylinder could be used if desired. There is shown a conduit 2'! extending between the drum and the cylinder 24 under control of a valve 28 and like conduits 29, 30 are provided for each of the cylinders 24' for therear set of elements.

After the cylinders 24 or 24' have been filled to capacity, which may be accomplished by jacking up the frame of the device to bring the pistons to their lower ends of the cylinders, with the valves 28 open, the valves 28 will be closed and kept closed during the operation of the device. Under these conditions an upward movement of one element will cause a compression of the liquid in the cylinder 23 connected thereto, which pressure will be equalized throughout all of the remaining elements with the eifect that the entire set of rear elements will be raised a proportionate amount but with equal pressure upon all of the elements.

The form of the invention illustrated in Figure 5 comprises a cylinder 23' containing a coil spring 32 reacting in compression between apiston 22' and an abutment 34 adjustabl in the cylinder by means of bolt 35 screw threaded in a cross member 36 of the frame. The piston 22 applies to the roller element its proportion of the weight of the frame upon the spring, through piston rod 20, as modified by the hydraulic action.

To prevent the escape of piston 33 from the cylinder, should its roller drop into a depression, a flanged collar 38 is provided upon the cylinder with its flange 39 underlying the piston.

It will be understood that, if all the roller elements were rigidly mounted in the frame, the riding of one roller over an eminence would require the lifting of the entire device with all the weight on that roller. With the springarrangement shown and the bolts 35 adjusted to bring all the springs to the condition shown in Fig. 5, the rising of one roller over such an eminence will compress its spring 32 with slight expansion of the remaining springs to keep the pressure on all rollers approximately uniform. However the pressure of the springs may be so adjusted as to force all of the pistons 33 against the flanges 39 in which event the pressure on all rollers cannot be equalized by expansion of the rollers on the common level, in which event an adiusted amount of pressure may be exerted up to a pressure suflicient to lift the whole weight of the device.

With the combination of the springs in the hydraulic cylinders, equipped with the flanged collars 38, any combination of the adjusted spring pressure with the hydraulic action may be had. Since a liquid is substantially incompressible, the combination may be adjusted up to the point of providing the effect of a rigid mounting of the roller elements in the frame.

By sufliciently slacking off the abutment 34 to relieve the springs 32 from compression a pure hydraulic action may be had.

Minor changes may be made in the physical embodiment of the invention within the scope of the appended claims without departing from the spirit thereof.

I claim:

1. In a device of the class described, in combination: a frame; a plurality of arms pivot-ed to the frame each on a horizontal axis; a roller element pivoted to each arm on a horizontal axis;

a hydraulic cylinder individual to each roller element and rigid with the frame; a piston acting in each cylinder; a piston rod connected to each arm and its corresponding piston; fluid filling each cylinder above its piston and means placing the respective cylinders into open communication.

2. The combination of claim 1 with a supply reservoir; a conduit connecting said reservoir with a common enclosed space opening into said cylinders; and a valve to close said conduit.

3. In a device of the class described, in combination: a plurality of roller elements mounted in a frame for vertical movement relative to each other and to the frame; hydraulic means reacting between the respective elements and the frame to normally transmit to each element a portion of the frame weight including cylinders to contain the liquid portion of said hydraulic means; means to place the cylinders for a plurality of said hydraulic means into open communication; and respective spring means coacting between the frame and said elements and supplementing and prising a plurality of cylinders individual to said roller elements, said cylinders in open communication with each other, and a substantially incompressible liquid filling the cylinders and communication spaces; means acting through said liquid to apply weight of the frame to said roller elements; and compression spring means coacting with said liquid in applying said weight; said spring means coacting between the frame and said elements and supplementing and modifying the action of said hydraulic means.

5. The combination of claim 4 with means to adjust a portion of the load applied to the spring means.

6. In a device of the class described, in combination: a plurality of roller elements mounted in a frame for vertical movement relative to each other and to the frame; a plurality of hydraulic cylinders individual to said roller elements and with their interiors in open communication; pistons working in said cylinders and connected to the respective roller elements to apply a portion of the weight of the frame to each roller through fluid in said cylinders; an abutment in each of said cylinders; a coil spring acting in compression between each abutment and piston; said springs supplementing and modifying the action of the hydraulic mechanism.

7. The combination of claim 6 with means to adjust the compression of said springs.

8. In a device of the class described, in combination: a plurality of relatively movable compacting portions; hydraulic means exerting pressure on each of said portions; the hydraulic means acting on the respective portions in open communication with each other, whereby to preserve substantially uniform pressure on the respective portions during displacement thereof relative to each other responsive to irregularities of a surface under compaction thereby.

9. The combination of claim 8 with means to apply excess pressure upon individual portions radically displaced away from the common plane of actionof the remaining portions.

10. In a road compactor, a frame, a ballast box suspended intermediate the ends of the frame, a pivot shaft extending transversely to the frame and supported at the lower rear end of the ballast box, a plurality of pairs of links pivotally secured to the shaft and extending rearwardly to a point underneath the rear end of the frame, a compactor wheel journaled for rotation between each pair of links, and yielding compression means between each pair of linksand frame.

JOE N. SUMMERS. 

